Can I obtain a complete neutral safety switch and plug for a 64 switch. 
- Non-Tilt/Turbo Hydramatic          - Part # 199 3652 (652 stamped on switch)

Then rewire my existing wiring to the new plug? Or can I just rewire my existing NSS? 

 My concern is I have changed the shift pattern from PND1D2R to PRNDL

Oh, I have a 63 convertible. 


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There is information in the Help topics on transmission swaps

 Thanks for the reply. Yes, I read that help section several times before I ventured into this project. A lot has changed in the ten years since it was written many parts are readily available that were not then. I’m in too deep to turn back now. Some fab is still needed. 

I still have the question if I can just rewire my existing switch (the preferred option) or would a switch from a 64 be the way to go?



I would be curious if you can post a list of the parts that are now readily available that were not when originally posted.  Other than the aftermarket adaptor ring I occasionally see, the THM kickdown switch, I have seen,  the longer front driveshaft section, different yaw mounts,  different carb mounting boss for switch, neutral safely switch differences and issues, shift quadrant indicator, and most importantly the different diameter (3 1/16" vs 3")  in raised mounting area off back of crank for for THM flex plate vs HM drive plate are still issues that you will have to deal with.  A THM flex plate will have to be enlarged to fit the back of the HM crank and it has to be done perfectly.    Thanks, Jason.


Speed Gems has a complete adapter kit that addresses the different diameter and flex plate issues.

Caddy Daddy has yoke,

Universal joint and trans tall mount and an explanation on the mod to the cross member. We still have to address linkage and shift quadrant indicator. As I mentioned I need to address the NSS and possibly front drive shat shortening.


Woah! $900. It is neat to see that mounting kit but you have other issues to deal with. 

As far as the yoke, you still need to install on an original driveshaft front section. The front sections are readily available.  It is the rear that is the issue. I have several VG condition for $100 for the HM front which is $165 less than the $265 Caddy Daddy is charging and you still have to have it installed. I am also not sure about the integrity of just extending the yoke length.  Under normal driving condition I would guess that would be OK.  That is basically extending the flexpoint further back from the tail shaft. In a 4x4 that would be a big non-no, but on an old Cadillac should be a good alternate solution.


I listed the yoke for information only for others if they are interested. We will not be using  the extended yoke. I'm using a TH400 with a 9" tail which is a a little longer overall then the Hydramatic. I had the same thought as you on the extended yoke. We will shorten the front shaft. This is a neat project that will be great when complete. I have a very accomplished mechanic with great fab skills. I'm sure there will be several trial and errors before complete.

The shift pattern is different, so ytou will need the 652 NSS.  However, the 652 will not bolt up to the 63 column.  You will need to swap out to a 64 non tilt THM column.   

Or you can jump the starter wires together and drive the car without back up lights. 

Thanks Russ, I was afraid a column swap was in to mix. 
I may go with the second option for now. Step back and regroup. Should be on the road in a couple of weeks. 

Thanks for the replies. 



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